- 1905 to 19093,219
- 1910 to 19199,332
- 1920 to 192910,098
- 1930 to 193910,286
- 1940 to 194915,900
- 1950 to 195914,979
- 1960 to 196922,679
- 1970 to 197914,381
- 1980 to 198914,415
- 1990 to 199910,673
- 20001,225
The preservation of the Duke University Libraries Digital Collections and the Duke Digital Repository programs are supported in part by the Lowell and Eileen Aptman Digital Preservation Fund